Method of discharging irreversibly dischargeable photographic filter layers



Patented Aug. 24, 1954 METHOD OF DISCHARGINGIRREVERSIBLY DISCHARGEABLEPHOTOGRAPHIG FILTER LAYERS Vsevolod Tulagin,

to General Aniline Binghamton, N Y., assignor & Film Gorporation,=-New"York, N. Y., a corporation of Delaware No Drawing. Application-August 9,1952, Serial No. 303,611

Claims. 1

The present invention relatesto irreversibly dischargeable photographicfilter and antihalation layers containing as the active filtering agent,a yellow Schiifs base and to a method of discharging such agent byutilizing aqueous solutions of amines having an aliphatic character.

Multilayer color film as presently manufactured is constructed in theform of an integral tripack comprising a base and three superimposedsilver halide emulsion layers thereon, sensitized respectively in theorder of their arrangement on the base to red, green and blue light.

It is well known that all high speed photographic emulsions are highlysensitive to blue light. However, in multilayer color film, the greenand red sensitive emulsions must not respond to exposure by blue light.For this reason, in present day manufacture of such film,-there isalways present, superimposed on the green sensitive emulsion, a filterlayer containing-a yellow colorant designed to absorb blue light andprevent its reaching and exposing the green and red sensi tive emulsionlayers.

The yellow colorant which is so. employed must possess certainfundamental characteristics in order to be eiiective for its intendedpurpose. In

the first place, it must be completely removed during the processing ofthe film since otherwise, the entire film would be colored yellow and itwould be impossible to obtain white or transparent areas. It is alsohighly desirable that the yellow colorant be non-migratory in thecolloidemployed as a carrier therefor. Should the colorant migrate from thefilter layer to an adjacent silver halide emulsion layer, it wouldseriously interfere with the spectral sensitivity of such layer andcolor degradation would inevitably ensue.

The colorant should be a brilliant one; that is to say, the colorantshould absorb a large percentage of blue light and yet be almostcompletely transparent in the green and red regions of the spectrum.

Finally, the colorant must be either Watersoluble or dispersible in anaqueous solution of the colloid serving as 'the'carrier. Manifestly, inthe absence of this property, the difliculties encountered inmanufacturing the filter layer would overbalance any other desirableproperties possessed by the colloid.

In my copending application Ser. No. 200,095, filed December 9, 1950,and entitled irreversibly Dischargeable Photographic Filter Layers andMethod of Processing Film Containing the Same, I have described a classof minus-blue colorants which can be readily made on a commercial scaleand which satisfy all of the above. prerequisites. In said application,it is suggested that these 2 yellow colorants be discharged by theutilization of a bath containing a base such as hydroxylamine,hydrazine, semi-carbazide or asalt of one of such bases. It hasbeen'found in commercial practicahowever, that when utilizing suchagents to discharge certain of the' yellow dyes of my prior application,unexpected di-fiiculties are encountered; Thus, it waslearned-thatcertain of the filter dyes when discharged as stated, leftobjectiona'ble residual stains. In addition, hydroxylamine "and*hydrazine solutions are highly poisonous-and may produce dermatitis inex tended use. Again hydroxylamine reacts readily with sulfite orhyposulfite and hence must be used as aseparate bath, therebyintroducing an extra step in the processing of the color film. Finally,the discharge agents mentioned in the prior application are not stableand would have to be replaced at least'onc a week.

- I have now discovered, quite surprisingly, that the above objectionsto the discharge agents of my prior application are'completely overcomeby using 'selected yellow dyes within the ambit of said application anddischarging such dyes by means of a bath containing an aliphatic oraralkyl primaryamine. The advantages of this discovery are manifold aswill appear from a consideration of the fact that suchamine solutionsare non-poisonous, are indefinitely stable and effect complete dischargeof the dyes without residual stain. Mor important still is the fact thatthe aliphatic and aromatic-aliphatic amines may tolerate the presence ofwater soluble sulfites, thiosulfites, bromides and chlorides and hencemay be used to effect dye discharge during fixing, bleaching, color-developmentor the like. For practical purposes, I have found that it ismost advantageous to add theamines employed for such discharge to thefixing bath.

Th yellow dyes found-to be efiective for my purpose are yellow Schiilsbases made by condensing a sulfonated aromatic hydroxy aldehyde of thebenzene or naphthalene series with a primary aromatic amin containing atleast one Water solubilizing sulfo or carboxy'group. The utilization ofsuchbases as colorants for filter and antihalation layers and thedischarge of such bases by means-of aliphatic and aralkyl primary aminesconstitute the purposes and objects of the present invention.

The yellow colorants, the utilization of which is contemplated herein,may be more aptly characterized by the following "structural'formula:

i in which M is hydrogen or a salt forming group hydroxyphenyl;Z-hydroxy-S-sulfonaphthyi; l-

hydroxy--sulfonaphthyl; 2 sulfo 6 hydroxynaphthyl;2-stearoylamino-l-sulfo-6-hydroxynaphthyl and the like and A is anaromatic radical containing a water solubilizing sulfo or carboxy groupsuch as l-sulfol-dodecoxyphenyl; lsulfo-4-octadecoxyphenyl;l-sulfol-octadecylsulfonamidophenyl l -sulfo-2-methyl-3-stearoy1-amidophenyl; l-sulfo-4-methyl-3-stearoylamidophenyl; 1-sulfo-4 methylamino 5 stearoylaminophenyl; 1-sulfo-4-octadecyl-aminophenyl;5-sulfo-l-octadecyl-2-phenylbenzimidazo1yl; sulfo-phenyl;1,3,6-trisulfo-naphthyl; l-sulfo-naphthyl; 1-sulfo-G-carboxy-naphthyl; l-chloro-3- sulfonaphthyl; l-methoxy 4 sulfo napththyl; carboxy-phenyl;carboxynaphthyl and the like.

In the above compounds, the hydroxyl group is always in ortho positionto the azomethin linkage. It has been found that the oxygen of thishydroxyl group is enolic in character since the hydrogen bond thereof islabile. This has been indicated in the above formula by the dotted linesrunning from the hydroxyl group to the nitrogen atom of the azomethinelinkage.

In the event that the above class of Schifis bases are to be used asfilter rather than antihalation dyes, then it is essential that there bepresent in either radical A or B, a group which renders the dyesnon-migratory in the colloidal carrier in which it appears. This resultis best achieved by incorporating in the dyes, an alkyl chain of atleast carbon atoms.

Examples of dyes which I have found to be suitable and which areembraced by the foregoing formula are the following.

I N\ OH H ols- (i /H3 OH 017E350 ONH- N=CEI- A0 3H 0 :K

N=CH- HOaS-N=CH 5 503K or:

N=CH

Naots N=CH NaOzSSOaNa 01K (7) OH NBC 0 011B (8) S 0 1H 0 H N=CH S O :K

NH O 0 01111::

OaNB

(11) CH: OH

011E150 ONE =oH- OzNa OsNa 12) s OSNa OH I do 3K A NH-CuHal 03K moreN==GHQNHC o own N: S OsNa N=CH HO OIK CuHliS OrN N=CH. CnHaaC O N- O 3N3OsH I l-OH:

OH H038 N=CH 03K K03 N=OH OONa aosmsas The above compounds are preparedby heating an ortho hydroxy: aldehyde of' the benzene or naphthaleneseries and bearing a sulfo group with a primary aromatic aminecontaining either a carboxy or sulfo group. Suitable aldehydes for thereaction are 2-hydroxy-benza1dehyde-5 sulfonic acid;2-hydroxy-naphthaldehyde-G-sulfonic acid; 1-hydroxy-2naphthaldehyde-4-sulionic acid; 2-hydroxy-6-stearoylamino-naphthaldehydel-sulfonic. acid; 6-hydroxy-5-formylnaphthalene-Z-sulfonic acid;6-hydroxy-5-formyl-2-stearoylamino-naphthalene-l-sulfonic acid and thecorresponding water soluble salts- Examples of aromatic primary aminesto be reacted with the'aforesaid aldehydes are2-dodecoxy-aniline-5-sulfonic acid; z-octadecoxyaniline -5-sulfonicacid; S-octadecane-sulfonamido ortnanilic acid;4-methyl-5-stearamidometanilic acid; 4-methylamino-6-stearoyl-metanilicacid; 4-octadecyl-amino-metanilic acid; 2 hydroxyOF-aminophenyl)-l-octadecyl-benzimidazole-E-sulfonic acid; sulfanilic acid; p-anilicacid 1 amino naphthalene; 3,6,8-trisulfonic acid;l-amino-naphthalene-8-sulfonic acid; 4- amino-benzoic acid;3-amino-benzoic acid; 1- amino-naphthalene-4-carboxylic acid; l-amino-4-carboxy-naphthalene-8-sulfonio acid; l-amino 8 chloronaphthalene-G-sulfonic acid; lamino 8-methoxy-naphthalene-4-sulfonicacid and the corresponding water soluble salts.

Practically all ofthe parent materials for the dyes contemplated hereinare described in the literature. Those which are not may be made by arelatively simple procedure. .Thus the sulfonic acid derivative of2-hydroxy-6-stearoylamino-naphthaldehyde isprepared by reducing2-hydroxy-S-nitro-naphthaldehyde with an'alkaline hyposulfite solutionfollowed by treatment of the cooled mixture with stearoyl chloride. Thealdehyde thus obtained is sulfonated with concentrated sulfonic acid at50-60 C. for several hours.

The amines mentioned above and having long aliphatic chains aredisclosedin' the copending application Serial No. 43,756, filed byJoseph Sprung on August 11, 1948, entitled. Silver Halide EmulsionsContaining Non-Difiusing Azo Dyes," now U. S. P. 2,629,658,datedFebruary 24, 1953, or in Fiat Final Report No. 943.

The filter layers of the present invention (it beingunderstood that theterm filter layers is to be construed to include. antihalation layers)are prepared by the incorporation of the dyes contemplated herein in acolloidal carrier therefor. As the carrier, there may be used the usualcolloids such'as gelatin,. polyvinyllalcohol, copolymers of maleicanhydride with methylvinyl ether and the like. The dyes are soluble inwater and hence may. be incorporated in the carrier by adding to. awater solution. of the selected dyestuff, slowly and with agitation, a10% aqueous solution of the desired colloid. Conversely, the dyes may bedissolved in water containing a little pyridine and such solutions usedto dye afoil ofthecarrier. Should the-foil-be gelatin, itwillbe'found.that those dyescontaim 7 ing a long aliphatic chain are quitesubstantive to the gelatin.

As previously emphasized, one of the important features of the presentapplication resides in the discovery that dyes constituted as above maybe readily and completely discharged by means of an aqueous solution ofa primary aliphatic amine such as methyl amine; ethyl amine; propylamine; monohydroxyethyl amine; l-amino-Z- hydroxy-propane;1-amino-2-hydroxy-butane; ethylene diamine; propylene diamine;polyethylene tetramine; cyclohexylamine; cyclobutyl amine and the like,or aralkyl primary amines such as benzylamine; B-phenylethyl amine; ,8-phenylpropyl amine and the like.

It is to be emphasized at this point that any aliphatic or aralkylprimary amine may be used providing that the amine dissolves in water toa certain extent. Preferably, the discharge bath comprises a 1-10%aqueous solution of the selected amine.

It has been noted previously that the aliphatic or aralkyl primaryamines may tolerate the presence of solutions of water soluble saltscontaining sulflte, thiosulfite, bromide or chloride groups.Accordingly, the amines may be incorporated in one of the usualprocessing baths and I have found it most advantageous to add the aminesto the fixing bath. A suitable bath for such purpose would beconstituted as follows:

Sodium thiosulfate gms 200 An alkali gms -50 An amine as indicated abovecc -100 Water to make 1000 cc.

The following examples serve to illustrate the invention but it is to beunderstood that the invention is not restricted thereto. Parts are byweight unless otherwise stated.

SECTION I PREPARATION OF DYEs Example 1 Into a container equipped with amechanical agitator and a reflux condenser there are introduced 200parts of pyridine, 120 parts of glacial acetic acid and 2 parts of thepotassium salt of 6- hydroxy-5-formyl-naphthalene-Z-sulforfic acid. Themixture is then heated just to the reflux point. An intimate mixture of1-octadecyl-2- ('-aminophenyl)benzimidazole-S-sulfonic acid (27 parts,30 mesh) and the potassium salt of 6-hydroxy-5-formyl-naphthalene-2-sulfonic acid parts, 30 mesh) is rapidlyintroduced. The resulting suspension is refluxed with agitation for 1hour. A solution of 5 parts of sodium acetate in parts of glacial aceticacid is introduced and the mixture refluxed for another hour. Themixture is maintained at 95 C. for another hour and the insolublematerial is collected by filtration. The so-obtained yellow filter dyeis washed with pyridine acetate and further with methanol. The washedcake is dried and the dye is used without further purification.

Example 2 The procedure is the same as in Example 1 excepting thatZ-amino-5-stearoyl-aminotoluenei-sulfonic acid is substituted for thebenzimidazole derivative of Example 1.

Example 3 The procedure is the same as in Example 1 excepting that4-octadecyl-amino-metanilic acid is substituted for the benzimidazolederivative, of Example 1.

Example 4 The procedure is the same as in Example 1 excepting thatsulfanilic acid is condensed with the potassium salt of6hydroxy-5-formyl-naphthalene-sulfonate in equimolecular quantities.This product is useful as an antihalation dye.

Example 5 The procedure is the same as in Example 1 excepting thatmetanilic acid is condensed with the potassium salt of6-hydroxy-5-formyl-naphtha1ene-2-sulfonate in equimolecular amounts. Avaluable antihalation dye is thus produced.

Example 6 Example 7 The procedure is the same as in Example 1 exceptingthat the potassium salt of 6-hydroxy-5-formyl-2-stearoyl-amino-naphthalene-l-sulfonic acid is condensed withsulfanilic acid in equimolecular amounts. I

Example 8 The procedure is the same as in Example 1 excepting thatpotassium salt of 6-hydroxy-5- formyl- 2 -stearoylamino-naphthalene-1-sulfonic acid is condensed with metanilic acid inequimolecular amounts.

Example 9 The procedure is the same as in Examplel excepting that2-hydroxy-benzaldehyde-5-sulionic acid is substituted for the aldehydeof Example 1.

Example 10 The procedure is the same as in Example 3 excepting that thealdehyde employed is Z-hydroxybenzaldehyde-S-sulfonic acid.

Example 11 To a solution of 1 mole of the potassium salt of6-hydroxy-5-iormyl-naphthalene-2-sulfonic acid in a minimum quantity ofboiling acetic acid are added 3 moles of pyridine andslightly less than1 mole of S-amino-naphthalene-l-sulionic acid. The mixture is boiled for3 to 5 minutes an then added to a large volume of ethyl ether. Theprecipitated dye is recovered by filtration, washed with acetone andused without further purification.

Example 12 A mixture of the potassium salt of 8-amino-6- Example '14 Theprocedure is'the same as in Example 13 excepting thatthere' is. used thedyestufi of Example 12.

SECTION III FIXING AND DISOHARGEIBATH "Example '15 The followingsolution serves as a combined yellow filter dye bleach an'd'fixingbath:

Sodium thiosulfate gms 200 Sodium metaborate 'gms 25 Ethanol amine cc 15Water to make 1000 cc.

Example 16 The-following solution serves as a combined filter dye-bleachand fixing-solution:

Sodium thiosulfate gms 200 Sodium carbonate gms .20 Benzylamine -cc 12Water to make 1000 cc.

Example 17 The following solution serves as a combined yellow filter dyebleach and fixing bath:

Sodium thiosulfate gms 200 Trisodium phosphate gms 30 Phenethyl amine cc15 Water to make 1000 cc.

SECTION IV PREPARATION or MULTILAYER FILM Example18 A red sensitizedsilver bromide emulsion containing a phenolic color former fast todiffusion was coated upon a base and over this is cast a green sensitivesilver bromide emulsion containing a pyrazolone color former fast todiffusion.

Over the green sensitive layer is cast a filter layer prepared from thesolution of Example 13. Over the filter layer is cast a blue sensitiveemulsion containing an acetoacetanilide color former fast to diffusion.

Example 19 The procedure is the same as in Example 18 excepting that thefilter layer is prepared from the solution of Example 14.

SECTION V FILM PROCESSING Example 20 Film prepared according to Example18 is exposed, developed in a black and white developer, washed,re-exposed and developed in a p-diethylaminoaniline developer. The filmis then bleached and fixed in the solution of Example 15 after which itis shortstopped and immersed in a sodium bicarbonate solution, washedand dried. It will be found that the yellow filter layer has beencompletely removed and that no yellow stains remain.

Example 21 The procedure is the same as in Example 20 excepting that thefixing is efiected with the bath of Example 16.

Example 22 The procedureis the same as in Example 20 excepting that thefixing is effected with the bath of Example 17.

Modifications of the invention will occur to persons skilled in the art.'I'hus it is evident that any of the aldehydes mentioned above may becombined with any of the amines to form satisfactory yellow colorantsfor filter or antihalation layers. Similarly, while the examples aredirected'to the use of the colorants in forming filters in colorphotography, it is to be understood that the colorants may be used toform filters and antihalation layers for black and white film. Finally,while the examples specify the use of the amines in the fixing bath, itis to be understood that they may also be used if so desired in thebleaching or color development baths.

'1, therefore, do' not intend to be limited in the patent granted exceptas required in the appended claims.

I claim:

1. In the processing ofan exposed light sensitive photographic elementcomprising a base and alight sensitive silver halide emulsion layer andincluding a water 'soluble'colloid dyed'withan irreversiblydischargeable'schi'ffsbase of the following formula:

in which B is an aromatic radical selected from the class consisting ofthose of the benzene and naphthalene series, A is an aromatic radicalcontaining a group selected from the class consisting of sulfo andcarboxy groups, M is selected from the class consisting of hydrogen andsalt forming radicals and the hydroxyl group is ortho to the azomethinelinkage, the improvement which comprises discharging said Schiifs baseby subjecting the photographic element to the action of an aqueoussolution of a primary amine selected from the class consisting ofaliphatic and aralkyl amines.

2. In the processing of an exposed light sensitive photographic elementcomprising a base and a light sensitive silver halide emulsion layer andincluding a water soluble colloid dyed with an irreversiblydischargeable Schills base of the following formula:

in which B is an aromatic radical selected from the class consisting ofthose of the benzene and naphthalene series, A is an aromatic radicalcontaining a group selected from the class consisting of sulfo andcarboxy groups, M is selected from the class consisting of hydrogen andsalt forming radicals and the hydroxyl group is ortho to the azomethinelinkage, the improvement which comprises discharging said Schifis baseby subjecting the photographic element to the action of a fixing bathcontaining a primary amine selected from the class consisting ofaliphatic and aralkyl amines.

3. The process as defined in claim 1 wherein the Schifis base containsan aliphatic radical of at least 10 carbon atoms designed to render itnon-migratory in the colloid in which it appears. I

4.. The process as defined in claim 2 wherein the Schiffs base containsan aliphatic chain of at least 10 carbon atoms to render itnon-migratory in the colloid in which it appears.

5. In the processing of an exposed multilayer photographic materialcontaining three light sensitive silver halide emulsion layerssensitized respectively to the red, green and blue regions of thespectrum and having interpolated between the green and blue sensitivelayers, a filter layer comprising a water soluble colloid dyed with anirreversibly dischargeable Schiffs base of the formula in which B is anaromatic radical selected from the class consisting of those of thebenzene and naphthalene series, A is an aromatic radical containing agroup selected from the class consisting of carboxy and sulfo groups, Mis selected from the class consisting of hydrogen and salt formingradicals and the hydroxyl group is ortho to the azomethine linkage, theimprovement which comprises discharging said base by subjecting thephotographic material to the action 12 of an aqueous solution of aprimary amine selected from the class consisting of aliphatic andaralkyl amines.

6. The process as defined in claim 5 wherein the primary amine islocated in the fixing bath.

'7. The process as defined in claim 5 wherein the Schiffs base containsan aliphatic chain of at least 10 carbon atoms designed to render itnon-migratory in the colloid in which it appears.

8. A photographic fixing and bleaching bath containing as the essentialcomponents an aqueous solution of sodium thiosulfate, an alkali, and aprimary amine selected from the class consisting of aliphatic andaralkyl amines.

9. A photographic fixing and bleaching bath containing as the essentialcomponents an aqueous solution of sodium thiosulfate, sodium metaborateand ethanol amine.

10. A photographic fixing and bleaching bath consisting of sodiumthiosulfate (200 parts), an alkali ranging from 0-50 parts, and analiphatic primary amine ranging from 10-100 parts by volume, the balancebeing water.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,078,398 Mannes Apr. 27, 1937 FOREIGN PATENTS Number CountryDate 571,389 Great Britain Aug. 22, 1945

1. IN THE PROCESSING OF AN EXPOSED LIGHT SENSITIVE PHOTOGRAPHIC ELEMENTCOMPRISING A BASE AND A LIGHT SENSITIVE SILVER HALIDE EMULSION LAYER ANDINCLUDING A WATER SOLUBLE COLLOID DYED WITH AN IRREVERSIBLYDISCHARGEABLE SCHIFF''S BASE OF THE FOLLOWING FORMULA: